Dynamo-electric machine



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G LOAMPBELL DYNAMO ELECTRIC MACHINE. 4 No. 575,210. Patented Jan. 1 1897.

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G'.L.OAMPBELL. V DYNAMO ELBGTRIG MAGHINE.

Patented Jan. 12, 1897.

WITNESSES.

ATTORNEYS.

projections a, to which are bolted the curved UNITED STATES ATENT rrica.

GEORGE LUMAN CAMPBELL, OF KINSMAN, OHIO.

DYNAiVlO-ELECTRIC MACHINE.

SPECIFICATION forming part of Letters Patent No. 575,210, dated January 12, 1897.

Application filed October 8, 1895.

To all whom it may concern..-

Be it known that I, GEORGE LUMAN CAMP- BELL, of Kinsman, in the county of Trumbull and State of Ohio, have invented new and useful Improvements in Dynamo-Electric Machines, of which the following is a full, clear, and exact description.

The object of my invention is to construct a dynamo in which the voltage and current may be easily and quickly regulated while the dynamo is in operation.

My invention consists in certain features of construction hereinafter described and claimed.

Reference is to be had to the accompanying drawings, forminga part of this specification, in which similar characters of reference indicate corresponding parts in all the views.

Figure 1 is a front elevation of myimproved dynamo. Fig. 2 is a side elevation. Fig. 3 is a side elevation of one of the sections of the field-magnet, and Fig. 4: is a rear elevation of the machine.

The armature A, which is of the ordinary well-known description, is journaled in the supports 13 B, attached to the base plate O. The support B in the present case has four arms 12, supporting the field-magnet sections D. In the outer end of each armb is formed an opening, in which is inserted a screwthreaded rod 0, which is slotted longitudinally and prevented from turning by a feather inserted in the arm Z).

The rod 0 is provided with a cross-piece E, having arms cl and c. The arm 6 is jointed to the end of the core of the magnet-section D, and to cars f, attached to the field-magnet core, are jointed swing-bolts g,which extend through the arms cl of the cross-piece E and are provided with nuts by means of which the field-magnet core may be adjusted by swinging it on its jointed connection with the cross-piece.

In the present case I have shown four field-magnet sections, but my improvement obviously will apply to a greater or smaller number. These core-sections are arranged radially around the armature A and are pro vided with pole-pieces adapted to the armature. On each screw-threaded rod cis placed an internally-screw-threaded miter-wheel F,

Serial No. 565,003. (No model.)

which 'is engaged by a miter-wheel G, mounted on a shaft II, journaled in bearings supported by the arm b. Each shaft H has on its outer end a sprocket-wheel I, upon which is placed a chain J, the said chain passing around all the sprocket-wheels and around a sprocket-wheel K, mounted on a shaft journaled at the center of the frame formed by the arms Z) and the standard B. The sprocketwheel K is provided with handles it, bymeans of which it may be turned so as to cause all of the shafts II and beveled wheels F to revolve simultaneously. The miter-wheels F are prevented from moving up or down on the screw on the screw-threaded rod by the arm I) and a plate i, attached to the end thereof. The plates 2', when the arms are in their lower position, also serve to partly carry the weight of the field-magnets, and thus relieve the pressure on the teeth of the miterwheels. The armature A is driven by means of a belt running over a pulley j on the armature-shaft.

By means of my improvement I may adapt the field-magnet to armatures of different sizes, and I may apply different pole-pieces, as may be required, the cores being for this purpose provided with dovetail slideways ranging longitudinally of the armature and adapted to receive the removable pole-pieces. (See Figs. 1 and 2.) The pole-pieces are practically quarter-sections of a rectangular prism of iron with the inner surfaces concaved to approximately conform to the shape of the armature. This construction provides asolid mass of iron around the armature and increases the efficiency of the machine. The pole-pieces are transversely grooved to prevent the formation of eddy-currents'and to increase the output of the machine.

The field-magnet sections are excited in the usual way, either by being connected up in series or in a shunt-circuit or being separately excited, according to the system on which the machine is constructed. When the field-magnet sections are near the armature, the voltage and amperage are the highest. \Vhen it is desired to reduce the curthe armature in radial directions, takingwith them the field-magnet sections. The strength of the field being thus reduced, the current is reduced accordingly.

It is obvious that when the field-magnet sections are removed from the armature and it is desired to strengthen the current the reverse of what has been described takes place.

Having thus described my invention, 1 claim as new and desire to secure by Letters Patent 1. The combination of the armature, fieldmagnet supports movable toward and from the arm ature field-magnets mounted to move with said supports and pivoted thereto to swing in planes extending longitudinally of the armature, and means'lor holding the holdmagnets in position, substantially as do scribed.

9. The combination of the armature, supports movable toward and from the arnmture, field-magnets pivotally carried by said supports, and means for holding the :lield-imag nets in position, substantially as described.

GEORGE LUMAN CAMPBELL. Witnesses:

R. H. KIDDLE, ALFRED 1. KiNsiLiN. 

